#!/bin/bash

which echo
which printf
which cat
which bat
which read
echo "which clear -------------------------"






echo "'1\n'"
echo -e "'2\n'"
echo -n "'3\n'"
echo -en "'4\n'"
echo "echo clear ==========================="






printf "[%8s] [%-8s] %08x\n" "abc" "123" "333"
echo "printf clear ------------------------"





cat /proc/uptime
cat <<< "here string"
cat <<- EOF_key
    this is a
    here document.
EOF_key
echo "cat clear ------------------------"





bat --pager=never $0
echo "bat clear ------------------------"





read -p "input a string: " str
echo "read string: $str"
echo "read clear ------------------------"
